Lay Waste is very strong at farming minions and harassing enemy champions.
Ask your allies to help point out when you should use Requiem to get kills in different lanes.
When laning against Sivir, it is possible to throw off the timing of her Spell Shield by faking an advance, then backing off.
Sivir is a powerful pushing champion, so leaving her unattended in a lane for too long will often result in your turrets being destroyed.
Boomerang Blade costs a lot of mana to cast, so dodging it sets Sivir back. If it hits you on the way out, avoid its path on the way back.
The stats provided here clarify some valuable Karthus vs. Sivir matchup statistics that can help us realize the distinctions between the pair. As an example, Karthus’s KDA ratio ([kills + assists] / deaths) of NaN is more than Sivir’s ratio of NaN, showing that Karthus may be more central to his team's team fighting capability than Sivir..
Karthus normally has a slightly larger longest kill spree than his opponent does. On average, he receives more damage than Sivir. This often reflects different amounts of tankyness, but it can also imply that the one champ has less mobility and thus is unable to escape additional harm when poked or engaged.
Both League champs are great champions. Both have their strengths, weaknesses, and counters. In the game's current meta, Karthus usually wins when trying to fight Sivir, with a 51.0% win rate. Thus, Karthus makes a good counter for Sivir.
While Karthus does have a higher winrate than Sivir, when they face off with one another, Karthus also has a much greater difficulty level that makes him a more time consuming character to pick up and master. You should be careful when picking Karthus into Siviras his relative depth means that you may not be able to unleash his full potential without a lot of practice beforehand.
Moreover, Karthus has some amount of CC and other utility, a similar amount to Sivir. This often makes her just as valuable during teamfights, especially when trying to counter champions with a ton of burst damage.
While there is not one best champion overall in League of Legends, in Karthus vs Sivir matchups, Karthus is the better champion with a similar win rate, more champion depth, and a similar amount of utility to help out your team members during teamfights.
Karthus is a decent counter to Sivir. Focus your tactics on keeping up your gold income and destroying objectives. If you are able to do that, you should do very well as Karthus against Sivir.
To learn all of the intricacies of Karthus in order to counter Sivir during both the laning and mid / late game phases of League of Legends, you should keep reading to learn a few extra tricks and insights into this matchup. If you listen to the build and suggestions displayed above, you will grow your win rate significantly and be closer to League of Legends pro players.
Karthus often gets less CS compared to Sivir. Champs who typically don't earn many minion kills often don't require much CS to be effective, such as sup champs. They are able to scale properly off of their abilities and first items alone. Yet, champs with a lot of CS, such as hyper-carries, typically require many items to be effective. In either situation, try to surpass the values shown on this page to do well.
The most important items to prioritize in your Karthus versus Sivir build consist of Malignance, Shadowflame, and Liandry's Torment. When Karthus incorporated at least these three pieces in his build, he performed a lot better vs Sivir than with many other common builds. In fact, Karthus had an average win rate of 51.0% battling Sivir with this counter build.
To have the greatest likelihood of crushing Sivir as Karthus, Karthus players should take the Dark Harvest, Cheap Shot, Eyeball Collection, Ultimate Hunter, Gathering Storm, and Transcendence runes from the Domination and Sorcery rune sets. Out of all the rune builds players chose for Karthus vs Sivir clashes, this sequence of runes resulted in the best win rate. Notably, these runes gave a 51.0% win rate overall.
If you need to see Karthus x Sivir tips and matchup stats and build suggestions for a a particular player tier, feel free to select one from the selection menu provided above. If viewing for the first time, the statistics and strategies shown are computed using all rounds completed with these champions.